The Global Positioning System (“GPS”) is currently the most well-known location information service system. GPS uses a satellite network to transmit signals to individual GPS receivers on the ground which then calculates receiver positions based on these signals. As the popularity of GPS has grown, GPS receivers are no longer only found in traditional stand-alone devices. The receivers are integrated as components in many different types of multi-functional devices. Some of the personal wireless mobile devices, such as cellular phones, have incorporated GPS receivers to allow users to instantaneously determine their locations and obtain directions.
In addition to GPS, Wi-Fi (IEEE 802.11) based location determining services have been developed in recent years. Software-only positioning systems now exist that leverage a nationwide database of known Wi-Fi access points to calculate the location of any Wi-Fi enabled device. The major benefits of Wi-Fi based location services, in comparison with GPS based location services, are that the Wi-Fi based service is less expensive and more accurate. In addition, because Wi-Fi based positioning system has no line of sight requirements, it has a distinct performance advantage over GPS when used indoors.
Currently, some single mode cellular mobile terminals incorporate a variety of GPS-based location determination technologies and systems. However, with the introduction of dual-mode 802.11/cellular mobile terminals, there is a need to utilize emerging Wi-Fi based location determination technologies and systems in conjunction with the existing cellular location determination technologies.
The present invention provides systems, devices, and methods that utilize dual-mode and multi-mode mobile devices for location determination.